A POTUS is a politician a Justice is not. So impeaching a president would not be as consequential as impeaching a justice, IMHO, purely on the basis that if you do it to a Justice, you officially drag the Justices square into the political sphere while a president already lives there. I just think it would lead to a perpetual which hunt (pardon that term) for all justices forever. I just picture the Breitbarts of the world with non stop headlines "SOTOMAYOR'S HUSBANDS CONNECTED TO COLUMBIAN CARTEL FINANCIAL CHIEF" and Deven Nunes demanding an investigation. That could be the final nail in the coffin for our institutions.
Now don't get me wrong, if it comes out that BK has committed verifiable crimes, then he should step down or be impeached. But, picking at how he paid his mortgage, seems too petty to raise a stink. And seeing that he went to Georgetown Prep and Yale, he probably paid for it the same way all of his classmates did, with his parents money.
And re impeaching Donald, I would love it, but only if something ironclad comes out showing an impeachable offense, which I have yet to see. Hopeful Mueller brings the goods. If not, let's vote that fucker out in 2020.